We have a cotoneaster which has been infested by little spiders. The webs seem to be causing the leaves to turn brown and die off - presuming the light can't get through as areas of the plant which don't have webs on are fine. So far I've been brushing the webs off regularly and the leaves have been coming back green but wondered if there was a less time consuming answer? Don't want to use an insecticide as we're keen to encourage the bees, which love the plant, into the garden.